ADTRAN 1200410L2, User Manual

Page: 42 / 80

Chapter 5. Configuration Menu
42 ESU LT User Manual 61200410L2-1A
Network (NI)
This menu is used to access the configuration of parameters
associated with the network interface in the ESU LT. There are six
submenu items that include setting the framing type, the line code,
and the clock source.
The fields and parameters available are listed in the following
sections.
Framing
The ESU LT can operate in three different framing modes:
Common Channel Signaling (
CCS
), Channel Associated Signaling
(
CAS
), or
U
NFRAMED
.
CCS
CCS uses a 7-bit pattern called the Frame Alignment Signal (FAS)
to establish and maintain frame synchronization. The FAS word is
located in timeslot 0 of even frames. Odd numbered frames may
contain the Not FAS word (NFAS) in timeslot 0. The ESU LT can
be configured to require the NFAS word for frame sync.
In CCS mode, there are 31 channels (timeslots 1-32) available for
user data. Timeslot 16 cannot be used to carry signaling
information in this mode.
CAS/TS16
CAS, also known as timeslot 16 multiframing, requires a
multiframe alignment signal to be present for frame sync. The
Multiframe Alignment Signal (MFAS) is inserted into the 16th
timeslot of frame 0 of the 16-frame multiframe. The MFAS word
consists of four zeros, an unused bit, the multiframe alarm bit, and
two more unused bits. Frames 1 through 15 carry the A, B, C, and
D bits for timeslots 1-15 and 17-32.
The ESU LT is designed for data transmission; therefore, the
signaling bits used for voice traffic are set to
A
LL
O
NES
.